Diffuse atherosclerosis precludes arterial reconstruction by conventional techniques, and results in gangrene and limb loss. Arteriovenous reversal (AVR) is a proposed revascularization procedure in which arterial blood is directed distally down a peripheral venous tree to distribute nutritive blood to the capillaries and tissues. In canine preparation with diffuse femoral arterial tree occlusion and an AVR, acute hemodynamic and metabolic studies will assess tissue viability and perfusion. Continued function will be studied by non-vasive physiologic techniques, angiography, and at sacrifice vascular structural changes will be evaluated histologically. The microcirculatory basis for these tissue effects will be analyzed. Survival of the limb and return to normal function following arteriovenous flow reversal will provide evidence that the procedure may be applicable in attempts at human limb salvage where arterial reconstruction has failed or is not applicable.